How to create movement area highlight with XCOM or Invisible.inc style

Hi everyone,
I’m making a gridbased tactical RPG game and try to create movement area highlight to show which tile that a unit can move into.

Currently im able to create mesh on runtime and using simple color material so its looks kinda bland.

Im want to change the look of this mesh into the style which XCOM or Invisible.inc have.

154613-images-11.jpeg

154614-images-14.jpeg

Can anyone give some advice on how to achieved this?
Thank you

could be using concave hull algoritm + line renderer first, second some type of shader based on previous algoritm.